In planning for getting a new puppy, I've begun thinking about how my life will change, especially for the first few months. In addition to going through housetraining, I'll be spending a lot of time on a hugely important aspect of its development, something that affects a dog's psychological health, learning and life view. It's called "socialization."

Socialization is the process of introducing a puppy to a diverse range of people, places and things. Through exposure to different things, a puppy learns to accept "the new" - new environments, individuals and activities.

Socialization strengthens a dog's coping skills, enabling it to tolerate and accept unfamiliar things throughout life. Especially significant in the first 12 weeks, socialization's importance to a puppy cannot be overvalued. Without it, dogs go through life fearful of and stressed out by anything new and unfamiliar.

Socialization is so crucial that in 2008 the American Veterinary Society of Animal Behavior issued a position paper stating that the importance of puppy socialization trumps the risk of illness. Prior to this, many veterinarians advised keeping a puppy home until around 16 weeks of age, even though two books published in the 1960s - "Genetics and the Social Behavior of the Dog" by John Paul Scott and John Fuller (1965) and "The New Knowledge of Dog Behavior" by Clarence Pfaffenberger (1963) - clearly reported the impact of lack of socialization. I first read these books in the early '70s, and they influenced my budding dog-training career. I've been lecturing and writing about the importance of socialization ever since.

Without socialization, a dog might act perfectly normal, outgoing and confident in familiar surroundings, but would lack confidence in an unfamiliar environment or situation. In the extreme, a dog might be so stressed and frightened in new situations as to be nearly catatonic.

I saw the effects of lack of socialization firsthand in England when a generation of dogs was not socialized. I first visited England in 1980 to teach dog training, returning annually for a two-week lecture tour. At first I was impressed by (and frankly envious of) the extent to which dogs were accepted everywhere. Dogs were extremely well-socialized, allowed on public transportation, welcomed in pubs and restaurants, participating in family outings and enjoying frequent walks along the myriad walking paths where dogs could romp off-leash.

Then in the early '80s, England experienced an outbreak of Parvovirus, and veterinarians started recommending that puppies be kept home until they were 5 months old. After a few years of adhering to this edict, fearful dogs were so prevalent in the next generation that I could no longer even find a dog to use for a demonstration at my training seminars. Virtually every dog I approached was frightened of strangers and stressed-out in the unfamiliar training venue.

As these were the offspring of dogs I had trained and successfully used for demonstrations just a few years earlier, this change was clearly not genetic temperament. The culprit was lack of socialization. Fortunately the pendulum has now swung the other way, and puppy classes are now widely accepted in England.

So if you have a new puppy, start off right. Seek out - and check out - a puppy class in your area. Ask your veterinarian for recommendations, and then talk with the trainer who runs the school to make sure the class offers what you are looking for: socialization and a broad range of positive, reinforcing, happy experiences.

Socialization doesn't mean necessarily including everything your dog might be exposed to in the future, but it's important to provide variety during this time when a puppy's development makes him accepting of new things. With early socialization, you're well on your way to having a well-rounded, emotionally healthy, normal dog. And I will be, too.